Mechanical telephone



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L. MELLETT.

MECHANICAL TELEPHONE.

No. 392,816 Patented Nov. 13, 1888.

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L. MELLETT.

MECHANICAL TELEPHONE.

No. 392,816. Patented Nov. 18, 1888.

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L. MELLETT.

MECHANICAL TELEPHONE.

No. 392,816. Patented Nov. 13. 1888.

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UNITED STATES PATENT LEMUEL MELLETT, OF JNlhYVTON, MASSACHUSETTS, ASSIG-NOR TO THE PULSION TELEPHGNE COMPANY, OF CONCORD, NEW HAMPSHIRE,

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 392,816, dated November 13, 1888. Application filed August 28, 1888. Serlal No. 253.978. (So model.)

specification.

This application is made in substitution for one heretofore made and filed in the Patent Office by Herman XV. Ladd and the present applicant jointly, June 2, 1887, Serial No. 240,093, covering the same identical subjectmatter.

The object of this invention is to produce a simple and most effective pulsioirtelephone, by which, without any electrical or magnetic current, human speech or other sound may be transmitted to a greater distance and in a more distinct manner than has been possible heretofore without such current. lVith my apparatus insulation of the wire is unnecessary, and for short distances ground-connections are desirable to reduce resonance. Supporting-coils of the wire at intervals wound around boughs of trees improve the transmission. I form branch lines without insulation to transmit to several points simultaneously from a single line and instrument. The first section of the wire is drawn taut; but the remainder may be I provide lateral openings from within the instrument for escape of the sound from behind the diaphragm, and preferably extend a smooth tube thence to one or both ears of the operator, to facilitate hearing while talking through the instrument. A spring press-button may close the aperture, when desired.

I utilize in my instruments the principle of harmonic vibration to project through the Wire to the receiver tones, words, and sounds from the transmitter, and by providing each instrument with a series of musical reeds, strings,or springs adapted to vibrate synchronously the one is in a receptive state, while the other transmits,and the simple wire connecting their diaphragrns pulsates with its messages without an electric or magnetic vehicle of trans: mission. I introduce the vibrators into the cavity behind the diaphragm, so that some of them will respondin both instruments to any tone or word uttered. Thereis asuitable metallic connection with the diaphragm, and preferably between the springs.

The apparatus may be mechanical] y charged with harmonic vibrations by a musical instru ment in preparation for use.

In the drawings, Fi ure l is a rear view of one of my improved instruments with the back removed to show the interior of the chamber, and Fig. 2 a transverse section of the same instrument. Figs. 3, r, and 5 are rear views showing other forms of vibrators, Fig. 6 is a transverse section of the device shown in Fig. 4:. Figs. 7 and Srcprcsent portions of the line with suitable supporting devices.

A represents the shell ol'the instrunient,enlarged to form a reed-chamber, B, and provided with the usual mouth-piece,0. I) is the diaphragm spanning the chamber B, secured marginally to the shell and having a central aperture and button by which to connectit to the line-wire E.

The chamberBcoutains, as shown,in rear of the diaphragm a suitable number of vibrators, F, which may be tuning-forks, musical reeds or strings, spring wires, or other devices adapted to be vibrated when the diaphragm is acted upon in reponse to spoken words or other sounds reaching it. These vibrators may be fixed firmly to the edges of the diaphragm or the walls of the chamber, with their free ends or vibrating bodies extending rearwardly or inwardly therefrom. For the best results the vibrators should be attuned similarly in both of the connected instruments, and each instrument should have a number ofthem,representing one or more octaves, so that the sounds uttered in any ordinary pitch or tone of voice shall each have at both ends of the line a chord pulsating in consonance therewith and forcing the sound forwai'd against all ordinary obstacles. The harmonic vibrators thus vitalize the conducting-power of the connecting-wire, greatly increase the power of the instrument by securing continuity of vibration, improve the tone by reason of the harmonic character of the series of vibrators, and give to the ap paratus as a whole capabilities hitherto un known.

IOO

Figs. 1. and 2 represent a series of spring wires coiled spirally and bent into-loops of varying sizes, which will vibrate to different tones, the wire being held securely to the diaphragm edges by washers and screws G between adjacent loops, or to the walls of the chamber by similar means. 13y preference I introduce a wire helix, Il,betwccn the diaphragm and the washers as a metallic connection between the several springs and the diaphragm.

Fig. 3 shows another form of vibrators, in which a series of connected spring-tongues are employed, representing the successive notes of the scale, and arranged to vibrate with any tones harmonizing with them severally. In Fig. 4-. the vibrators are musical strings of ya rying lengths stretched across the chamber under tension, as in a harp or piano, and vibrating in harmony with their corresponding notes and in unison at both ends of the line when the diaphragm is vibrated by any tone or sound. The strings may be provided with means of adjustment; to regulate their tension and tone. Fig. 5 shows a single spring-vibrator, coiled about as in the socalled cathedral gongs for fine clocks. One or more of these may be used in each instrument with the boss or hub I, in which its end is fixed in metallic connection with the diaphragm.

The line-wire E starts from the instrument with sufficient strain to put the diaphagm nnder proper tension; but it is not requisite that the whole line be taut. I therefore provide short guy-wires J, attached to the line-wire near the instrument and secured to any suitable support, as in Fig. 7. Beyond this point the line-wire may be slack and grounded, or may come in contact with trees or buildings, without losing the power of transmission.

I. am accustomed to stretch the wire E from treeto tree, or to support it, without insulation, on poles or buildings. At some of the points of support I form coils It by winding the wire spirally several times around the wooden support, with the successive coils by preference separated a slight distance from each other. 1 make no present claim to this feature of invention.

I have represented in Fig. 8 the line I] extending from the transmitter and branching into several lines, M, each to be provided with one of my improved instruments, working in unison with the transmitter. I am thus able to send the same message simultaneously to several different points, and deliver it at each point in a perfectly-audible manner.

Figs. 2 and 6 represent a feature of this inventionin which lateral openings are formed through the shell in rear of the diaphragm to afford escape for the sound into the room. I prefer to extend from these openings flexible or other tubes N, having a smooth bore and extending with a suitable curve around to the vicinity of the operators'ears and there terminating in the diverging ear-pieces 0. By this apparatus the operator can talk and hear through the line without changing the position of his head, and the sounds reproduced from the rear surface of the diaphragm are utilized.

In September, 1831, Mr. Charles Wheatstone recorded in the Journal of the Royal Institution, England, that if two musical instruments placed .in separate rooms were connected bya wire the playing upon one of them caused the strings of the other to vibrate. In place of such musical instruments I substitute telephones having vibrating diaphragms and resonant chambers with vibrators within them, and by these changes make practical use of the scientific observation referred to for the perfect transmission of human speech.

I am aware that in electric and magnetic telegraphs and telephones the vibration of musical reeds has been made use of to make and break the electric or magnetic currents; but I am not aware of any use of vibrators in telephones not employing such current prior to my invention. In electric and magnetic telephones the diaphragms are not directly connected by the line-wire, as they are in my instruments.

I make no present claim to the improved process or method of mechanical telephoning, which may be carried on by apparatus similar to that herein shown and described.

I claim as my invention- 1. The combination of a shell having a chamber therein, a diaphragm, a line-wire connected to said diaphragm, and a vibrator located in said chamber, for the purpose set forth. 4

2. The described pulsion-telephene, consisting of a transmitter and receiver with a linewire connecting their diaphragms, and with harmonic vibrators within the chambers of said instruments, substantially as set forth.

3. The shell A, having month-piece 0, dia phragm D, and wire E, directly connected to the diaphragm, in combination with one or more vibrators, F, within such shell, for the purpose set forth.

4. In a noneleetric and non-magnetic telcphone, the plain or uninsulated wire E and the diaphragms D directly connected thereby, in combination with the transmitting and recciving instruments containing vibrators F, attuned in harmony in the connected instruments, for the purpose set forth.

5. The improved telephone described, consisting of a transmitter and a receiver united by a wire connecting their diaphragms, in combination with a series of vibrators, F, at tuned in harmony in the two instruments and each series representing a succession of musical notes, for the purpose set forth.

6. The described pulsion-telephone having a series of harmonic vibrators in each IllSiJl'lb ment and the diaphragm connected by aplain uninsulated wire drawn taut at the end sections, but slackened elsewhere along the line, as desired, for the purpose set forth.

7. In a non-electric and nonmagnetic tele phone system, the shells A, having vibrators or more lateral openings in the walls thereof, F, diaphragms D, and the plain line-Wire E, in combination with the diaphragm D, vibraextending from the transmitter and diverging tors F in rear of the diaphragm, and wire E, I 5 into two or more branch lines, M, having like for the purpose set forth. instruments, for the purpose set forth. I In testimony whereof I have signed my name 8. In a telephone, the chamber B and vitothisspeeifieatiomin the presence of two subbrators F therein in rear of the diaphragm, l scribing witnesses, on this 23d day of August, with one or more lateral openings therefrom, A. D. 1888.

in combination with the tubes N, leading from LEMUEL MELLETT.

such openings, and with the earpiece O, for Witnesses: the purpose set forth. I A. H. SPENCER, 9. The shell A, having chamber B and one i H. XV. LADD. 

